Electric switch



l Nov. 8, 1932. B. E, GETcHl-:LL 1,886,477

ELECTRIC SWITCH Filed March 23, 1951 5 Sheets-Sheet 2 HNENTOR Benq/femurE' Gata/yell,

Nov. 8, 1932.l B. E. GETCHELL 1,886,477

ELECTRIC SWITCH Filed March 23, 1931 5 Sheets-Sheet 3 89 i .L mvEmOR,miss 9 l o .Bend/W Getcjre/, BY A 7V if Patented Nov. 8, 1932r UNITEDSTATES PATENT OFFICE BENJAMIN E. GETCHELL, F PLAINVILLE, CONNECTICUT,ASSIGNOR TO THE TBUMEULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVIIJLE,CONNECTICUT, A CORPORA- TION OF CONNECTICUT ELECTRIC SWITCH Applicationled Iarch 23, 1931. Serial No. 524,652.

My invention relates particularly to the class of enclosed switches inwhich provision is made for the manual operation of the switch undernormal circuit conditions and additional means is provided for causingthe automatic operation of the switch under predetermined overloadconditions.

One object of my invention is to provide an extremely compact but a veryrugged and reliable switch of the enclosed type.

Another object is to provide a normally hand operated switch with a verysimple but dependable form of automatic thermostatic release.

Another object is to provide a thermostatic overload mechanism whichnormally automatically resets the latching mechanism after being trippedby an overload and in which the latching mechanism may also be reset bymeans of the manually operable handle.

Another object is to provide an automatic thermostatic overloadmechanism which is trip-free from the manual operating means and whichcannot be prevented from operating by holding the manual operatinghandle.

Another object is to provide a doublebreak switch construction withwhich it is possible and perfectly safe to jo edge or inch a motor bymomentarily losing the contacts of the switch.

Another object is to provide an automatic switch construction having abi-metallic thermostatic element which is inuenced by a separate heaterelement and in which the heater element is readily removable withoutdisturbing any other part of the construction, and readily replaceable.

Another object is to provide a switch of lo the orementioned type inwhich practically all of the parts may be cheaply made of moldedmaterial and sheet metal stampings and which may be readily assembled ata minimum cost.

Another object is to provide an automatically operated thermostaticswitch mechanism which may readily be calibrated at the factory and inwhich the pre-determined calibration may be permanently set by means auof solder or an equivalent.

In the embodiment of the invention illustrated herein the switchincludes an insulating base which supports the line and load terminals,the stationary switch contacts and the thermostatic elements. It alsosupports a :trame which carries an operating lever and toggle mechanismof a special type which is adapted to be secured to the base by a singlescrew. The base is provided with grooves, pockets and barriers forlocatino' the various conducting and actuating mem ers. The switch is ofa compact form adapted to be mounted in a protective box or casing,

having a hinged cover and a latch. The handle or operating lever of theswitch eX- tends through this cover.

Fig. 1 is a front view of an enclosed switch embodying my invention.

Fig. 2 is a side View of the same, a part of the cover being brokenaway.

Fig. 3 is a front view of the interior mechanism on a scale representingfull size.

Fig. Il is an end view of the same showing part of the thermostaticrelease.

Fig. 5 is a longitudinal section showing the parts of the switch in theclosed circuit or on position.

Fig. 6 is a fragmentary view of parts of the mechanism in one of thepositions they would occupy just after the switch has been tripped orreleased by action of the thermostatic device.

Fig. 7 is a rear View of the construction shown in Figs. 3 and 4.

Fig. 8 is a perspective view showing the movable carrier for the switchplates and coacting parts of the operating mechanism.

Fig. 9 is a perspective view of the latch member which coacts with thethermostatic device.

Fig. l0 is a side view and partial section showing parts of the switchmechanism in the position they occupy when the switch is off and thecircuit is open by reason of manual operation.

Fig. 11 is a side view and section showing a thermostatic element andits connections.

Fig. 12 is a front view of the frame and section of the operating lever.

Fig. 13 is one form of a heater element L00 to break the circuit quicklywith a snap action.

For the automatic release of the switch I provide two thermostaticdevices, which are connected in the two outer branches or lines of thecircuit. Each of these thermostatic devices consists of a bi-metallicarm 80 having one end secured to the bracket 81 and the other endconnected to a threaded rod 82. The bracket 81 is connected by a screw83 to a bushing 84, embedded in the insulating base. The bracket 85 isconnected by a screw 86 to another embedded bushing 84 and by a screw f87 to one ot the stationary contacts such as 8G. The terminal plate 30is connected by a screw 88 to the bushing 89, which is moulded in thebase and has a projecting hearing 90. A plate 9i has a linger 92 pivotedin the bearing 90 and a spring 93 is mounted on the rod 82 between thetherinostatic strip 80 and the plate 91. The rod 82 is preferably in theJform or' a screw with a nut 94 on its outer end which may be adiustedand soldered in place to regun late the device to act at the properoverload condition. The two plates 91 on opposite sides are connected byvan insulating bar 95, and this in turn carries an abutment catch 96which is positioned between the two extensions 97 of the trame where itis adapted to coact with the tail ot a latch lever 98.

A heater element 10.7 is interposed in the circuit between the bracket85 and the load side terminal plate 30 and is detachably seicured inposition by means of screws such as 86 and 88.

A similar heater element is also interposed Ain the opposite leg of thecircuit between the bracket corresponding to bracket 85 and the terminalplate 32.

The heater elements be made in various capacities or ratings by usingwider, narrower, thicker or thinner metal or by substituting a wirewhich may be coiled or otherwise formed but, in all forms, the elementsare provided with end portions suitable for interchangeable. attachmentby means ot screws 86 and 88.

rlhe moment of action of the loi-metallic thermostatic clement isdetermined by the rating or capacity of the heater element and,obviously, the moment ot action be changed it so desired substitutingsuitably marked heater elements of the desired capacity.

It will be readily apparent from Figs. 8 and 11 that the heater elementsare readily removable from the front of the base without disturbing anyother part ot the construction. It will also be apparent from Fig. 11that the contacts 88 and 86, the movable contact plate 40, spring 45 andspring cap 48 are all readily removable for replacement or repairs.

In manufacturing practice, these switches are calibrated at the factorywith standard heater elements, the calibrations being accomplished byadjusting the nut 94 on the screw 82 so that the switch willautomatically trip to open position under certain conditions and, whenso calibrated, the nut 94 is soldered to the screw 82 so that anyvariation from the moment of action may be prede-vk termined by thesubstitution of suitablyr`^ marked heater elements.

The lever 98 has lugs 99 which are pivoted in holes 100 in the sideplates of the frame. The other end of this lever 98 is pivoted to links101 which are connected to the pin 65 previously described. In thenormal olf or open circuit position of Fig. 10, the arm 96 is interposedin the path of possible movement of lever 98 so thatl the link 101 andthe pin are, in effect, stationary or fixed.

In case of an overload which heats a heater element which in turn causesa thermostat strip 80 to warp to a sullicient extent the inner end ofthe strip 80 moves upwardly and thus rocks the plate 91 and the attachedcross bar 95 so that the arm 96 is tilted downwardly out of the path ofthe movement of the lever 98. This leaves the le rer 98 free to swing onthe axis oi the pins 100, under the pressure of the spring 49, exertedthrough the cross bar 48, rods 72, 78., bars 64 and the pivot 66, (whichis now stationary so that the pin 65 moves toward the hase in the slots68), and exerting pressure on the short arm of the lever 98, tilts thelever to the position shown in Fig. 6. As soon as the bars 64 have movedsufficiently to release the rollers 7 6 from the notches 'l5' the actionof the spring 49 moves the parts to open circuit position with a snapaction.

The handle then drops to its oli position by its own weigh-t and this,in turn, restores the lever 98 to its original position and as soon asthe striphas cooled suliiciently, arm 96 returns to its originalposition and automatically latches the lever 98a It thehandle is held inthe on, or closed circuit position while the switch is beingautomatically tripped by an overload. arm 96 gets into the path of thelever 98 and prevents the weight ot the handle from automaticallyrelatching the mechanism and tc re-set the latch, it is merely necessaryto press downwardly on the handle 23 and move the handle to fully offposition whereupon the lever 98 moves to the latched or re-set positionas shown in Fig. 5.

This movement of the lever 98 is caused by the engagement of the upperright hand inclined edge of the slot 75 in the lever 55 with the roller7 6 carried by the floating lever or bar 64. As the upper end of thefloating lever is held in position by the cross pin 67, the lower end ofthe lever with the pin 65 is forced outwardly which pulls on the link101 and thus swings the lever 98 about its pivot 100.

-No thermostatic device is required in the central or neutral line butthe contact 37 of -the switch in this line is connected by a wire 105 tothe load terminal 31.

It will be seen that the thermostatic strips 80 are located in passages106 which extend through the base so that there is room forconsiderablecirculation of air to permit the strips to cool of in normalopera-tion and` prevent overheating.

.-The parts of the switch are designed to opcrate normally with the base14 in a vertical position as on a side wall. It will also operate in theusual manner manually when the base is horizontal. If the switch ismounted with its base horizontal and it is tripped thermostatically,gravity will cause the lever 98 to fall out of engagement with the arm96 in which event the pin 65 will fall to the bottom of the slots 68 andthe pin 66 will remain in the lower part of the slot 75. To reset theswitch it is then merely necessary to force the operating lever 23 tothe off position whereupon the lower edge of the inclined slot 75 willraise the roller 76 and the pin 66 so that the bars 64 will swing aboutthe pin 67 as a pivot and the links 101 will swing the lever 98 aboutits pivots 100 until the outer,

end of the lever arm 98 re-engages the end of the latch arm 96 rovidedof course the thermostat has coolelloil' sufliciently to permit the arm96 to return to its normal position. The switch however can not be resetuntil the thermostat has cooled oil to a suicient degree.

In case the switch is in the on position and the cover is opened theupper edge of the opening 21 will engage the lever 23 and move itsufliciently to throw the switch to the fully -ofi or open circuitposition automatically.

I claim:

1. An electric switch including an insulating base having sets ofstationary contacts, an insulating cross bar mounted between opposedcontacts, switch plates carried by said kcross bar for engagement withthe stationary contacts, an operating lever supported by the base, afioating lever having means of connection to said cross bar and withsaid operating lever, a thermostatic device having a heater connected incircuit with at least some of said contacts, a latch lever connected tosaid floating lever and a catch coacting with said latch lever to holdthe same in latched position under normal load conditions, means ofconnection between said operating lever and said floating lever formanually actuating the mov- 'able switch plates independently of thethermostatic devices, said thermostatic devices being adapted'to releasethe switch independently of said operating lever.

i I2. In an electric switch, an insulating base, stationarycontactsmounted thereon, movable switch plates for engagement with saidstationary contacts,a supporting frame mounted in said base, anoperating lever pivoted to said frame, a oating lever aving slottedconnections with said frame and having means of connection with saidmovable switch plate, a latch lever hinged to said frame andconnected'to said floating lever and a thermostatic element having acatch coacting with said latch lever, said frame, floatin lever andoperating lever being detachab e as a unit and independently of saidthermostatic device.

3. In electric switch including an insulatmg base having a set ofstationay contacts, a cross bar mounted adjacent thereto, contact platescarried by said cross bar for engagement with the stationary contacts,an operating lever supported by the base, a floating lever having meansof connection to said cross bar and with said operating lever,thermostatic devices having heaters connectedhin circuit with some ofsaid contacts, a latch lever connected to said fioating lever and acatch coacting with said latch lever to hold the same in latchedposition under normal load conditions, said thermostatic devices beingconnected to automatically actuate said catch, and means of connectionbetween said operating lever and said floating lever for actuating themovable contact plates independently of the thermostatic devices.

4.. In an electric switch, an insulating base, stationary contactsmounted thereon, a movable switch plate for engagement with saidstationary contacts, an insulating carrier for said plate, a supportingframe detachably mounted in said base, an operating lever pivoted tosaid frame, a floating lever having .slotted connections with said frameand having means of connection with said carrier, a latch lever hingedto said floating lever, a thermostatic device having a catch coactingwith said latch lever, and a single screw for securing said frame,

to said frame and linked said floating lever and said'operating lever asa unit to said base independently of said thermostatic device.

5. In an electric switch, an insulating base, stationary contactsmounted thereon, movablel switch plates adapted to coact with saidstationary contacts, an insulating carrier for said plates, a supportingframe mounted in said base, an operating handle lever pivoted to saidframe, a floating lever having slotted connections withl said frame,push rods connected to said lever and engaging said carrier, a latchlever hinged to said frame and linked to said floating lever, and athermostatic device having a. catch coacting with said latch lever.

6. An electric switch including lan insulating base having a set ofstationary contacts, a cross bar mounted adjacent thereto,- contactplates carried by said cross bar for engagement with the stationacontacts, an operating lever supported by t e base, a fioating leverhaving insulating connector bars hinged thereto and for engagement withsaid cross bar and connected to said operating lever, thermostaticdevices having heaters connected in circuit with some of said contacts,a latch lever connected to said floatingr lever and a catch coactingwith said latci lever to hold the same in latched position under normalload conditions.

7. An electric switch including an insulating base, a set of stationarycontacts mounted on said base, an insulating cross bar mounted adjacentsaid contacts, movable contact pla-tes carried by said cross bar forengagement with the stationary contacts, a spring pressing said crossbar outwardly, an operating lever supported by the base, a floatinglever, an insulating connector rod connecting said cross bar and lever,a sliding connection between said floating lever and said operatinglever, thermostatic devices having heaters connected in circuit withsome ot' said contacts, a latch lever connected to said floating leverand a catch coacting with said latch lever to hold the same in latchedposition under normal load conditions.

8 ln an electric switch, an insulating base, pairs or stationarycontacts mounted on said base, movable switch members for bridging saidpairs oit contacts, a carrier for said switch members, a pivotedoperating lever carried by the base, a bar having a sliding connectionwith said lever, insulating links connecting said bar with said carrier,a pivoted latch member, a link connecting said latch member and saidbar, a thermostatic member secured to said base, a catch 'for said latchconnected to said thermostaticmember to be actuated thereby, a heaterelement for said thermostatic member, a circuit terminal connected toone end or the heater element and A)n an electric switch, an insulatingbase, a pair o" stationary contacts mounted on the iront n the base atone end thereof, a

Y switch member adapted to connect said contacts, a carrier for saidswitch member, a pivoted operating lever carried by the base, a barhaving a sliding connection with said lever, a link connecting one endof said bar with said carrier, a pivoted latch member, a link connectingsaid latch member at the oposite end ci said bar, a thermostatic memersecured to the rear of said base, a catch for said latch connected tosaid thermostatic member to be actuated thereby, said thermostaticmember, said catch and said latch being housed in the end of the baseopposite said contacts, a circuit terminal, a heater having one endconnected to said terminal,

' means of electrical connection between the other end of the heater andone of said contacts and a circuit terminal connected to the othercontact, said heater serving to move the thermostatic member.

10. An electric switch including an insulating base having ockets,stationary contacts located in said) pockets, a cross bar mountedadjacent thereto, contact plates carried by said cross bar and coactingwith the stationary contacts, a spring pressing said cross baroutwardly, an operating lever supported by the base, a floating lever, aconnector rod connecting said cross bar and lever, a sliding connectionbetween Said floating lever and said operating lever, a latch leverconnected to said floating lever, a catch coacting with said latch leverto hold the same in latched position under normal load conditions and atherinostatic device for movi ing said catch.

1l. An electric switch including a base haV ing pairs of stationarycontacts mounted thereon, a cross bar mounted adjacent to said contacts,contact plates carried by said cross bar for bridging the respectivepairs of stationary contacts, an operating lever supported by the base,a iloating lever connecting said cross bar and said operating lever, athermostatic device having a heater connected in circuit with some ofsaid contacts, a latch member connected to said floating lever and acatch coacting with said latch member to hold the same in latchedposition under normal load conditions, said thermostatic device beinerconnected to automatically actuate said catch, and means of connectionbetween said operating lever and said floating lever for actuating themovable contact plates independently of the thermostaticdevices.

l2. An electric switch including supporting means having pairs ofstationary contacts, a cross bar mounted between opposed contacts,contact plates carried by said cross bar for bridging engagement withthe respective pairs ot stationary contacts, an operating leversupported by the supporting means, a floating lever connecting saidcross bar and said operating lever, a thermostatic device having aheater connected in circuit with at least some of said contacts, a latchlever connected to said lloating lever and a catch coacting with saidlatch lever to hold the same in latched position under normal loadconditions, means of connection between said operating lever and saidfloating lever for manually actuating the movable contact platesindependently of the thermostatic device, said thermostatic device beingadapted to release the switch independently of said operating lever.

13. In an electric switch, a base, pairs of stationary contacts mountedthereon, movable switch plates for bridging engagement with therespective pairs of said stationary contacts, a supporting framedetachably mountconnection with said operating lever and said frame andhavin y said movable switch plates, a latchA member pivoted to saidframe,

'l being y switch means of connection with hinged to said frame andconnected to said floating lever and a thermostatic device having acatch coacting with said latch member, said frame, floating lever andoperating levei` detachable as a unit and independently of saidthermostatic device.

14. In an electric switch,-a base, pairs of stationary contacts mountedthereon, movable lates adapted to connect the respectivev pairs of saidstationary contacts, a carrier for said plates, a supporting framemounted on said base, an operating handle a fioatin lever havinconnection with said frame an said handle, ush rods connected to saidlever and engaging said carrier, a latch member hinged to said frame andlinked to said floating lever, and a thermostatic device having a catchco- A acting with said latch lever.

15. In an electric switch, a base, pairs of stationary contacts mountedthereon, a movable switch plate for connecting each pair of saidstationary contacts, a carrier for said 'l plate, a supporting framedetachably mount- 30 `carried by said cross ed on said to said frame,

. Vfloating lever, a thermostatic base, an operating member pivoted aoatiiig lever having connection with said frame and member and havingmeans of connection with said carrier, a latch lever hinged to saidframe and linked to said device having a catch coacting with said latchlever, and a single screw for securing said frame with its attachedparts as a unit to said base independently of said thermostatic device.

16. An electric switch including a base having a pair of stationarycontacts mounted thereon, a cross bar mounted adJacent said contacts,contact plates carried by said cross bar for engagement with thestationary contacts, an operating lever supported by the base, a oatinglever having-.connector bars hinged thereto and engaging said cross bar,said floating lever having aI slotted connection to said operatinglever, ltliernostatic devices having heaters connectedin circuit withsome of said contacts, a latch member connected to said ioa'ting leverand a catch coacting with said latch member to hold the ssaine inlatched and manually operable posi- `tion-under normal load conditions.

17. An electric switchoincludingsupporting means, pairs of stationarycontacts mounted onvsaid means, a cross bar mounted adjacent saidcontacts, movable contact plates bar for electrically connecting thepairs of stationary contacts, a spring pressing said cross baroutwardly, an operating lever, a Boating lever having a slid- Yingconnection with said operating lever and connected to said cross bar,thermostatic means having heating means connected in circuit with someof said contacts, a latch `V g a catch for said latch member connectedto be actuated by the thermostatic member, a heater element for saidthermostatic member, a circuit terminal connected to one end of theheater element and means of electrical connection between the other endofthe heater element and one of said stationary contacts and a circuitterminal connected to a co-related 'stationary contact.

19. An electric switch including an insulating base having pockets,pairs of stationary Acontact-s located in the respective pockets, a

cross bar mounted in the base, contact plates carried by said cross barfor connecting the respective pairs of stationary contacts, spring meanspressing said cross bar away from said contacts, an operating leversupported by the base, a floating lever, a connector connecting saidcross bar and floating lever, a sliding connection between said Heatinglever and said operating lever, a latch lever coacting with saidfloating lever,fa catch coacting with said latch'lever 'to hold thesaine in latched position under normal load conditions and athermostaticdevice lfor moving said catch, said operating lever being adapted toreset said latch lever.

BENJAMIN E. GETCHELL.

In an electric switch, a base, pairs of lever and a push con- I Nov. 8,1932. B. HocKEN INDICATING AND CONTROLLING APPARATUS Filed NOV. 2l. 19272 Sheets-Sheel',

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